<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<button>获取json</button>
</body>
<script type="text/javascript" src="http://apps.bdimg.com/libs/jquery/2.1.4/jquery.min.js"></script>

<script>
    $('button').click(function(){
        $.ajax({
            type:'GET',
            url:'http://localhost:3000/first',
            headers:{
                "Conten-Type":"http://localhost:3000/first"
            },
            success:function (backDate) {
                // body...
                console.log(backDate);
            }
        })
    })
</script>
</html>